Okay, we are tasked with adding 509 and 2107. Let's begin!

Step 1: We'll start by adding the digits 9 & 7 in column 1 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 0 & 0 in column 2 and get 1.

Step 3: We'll start by adding the digits 5 & 1 in column 3 and get 6.

Step 4: We'll start by adding the digits 0 & 2 in column 4 and get 2.

So, 509 + 2107 = 2616.

